Art of treating and drying cereal grains.



A. P. ANDERSON. ART OF TREATING AND DRYING CEREAL GRAINS. APPLIOATION FILED APR.24,1907. RENEWED FEB. B, 1912.

Patented Aug. 20, 1912.

- 7/1 Z//62 J/amm/er jnaenson.

UNITED STATES PATENT OFFICE.

ALEXANDER P. ANDERSON, OF CHICAGO, ILLINOIS.

ART OF TREATING AND DRYING CEREAL GRAINS Specification of Letters ratent.

Application filed April 24, 1907, Serial No. 870,005. Renewed February 8, 1912. Serial No. 676,441.

scription, reference being had to the accompanying drawing, forming a part of this specification.

My invention relates to an improvement in the art of treat-ing and drying cereal grains of all kinds, either hulled or unhulled, or in a comminuted form,as for example, pearl hominy, pearled barley, grits and the like.

The process comprises two steps, the first of which, broadly considered, consists in heating the moisture-saturated rains in an air-tight cylinder or drum unti a pressure of about 10 to 50 pounds per square inch develops or until a temperature of about 110 to 150 degrees 0., has been reached. During the heating process the grains are stirred or a itated by a continuous rotation of the cylin er.

The second step, which preferably follows the first step immediately, consists in subjecting the grains thus treated to the action of a vacuum pump until the grain is dried down to the desired dryness,for example, to an air-dry condition.

One of the objects of my invention is to convert unhulled cereal grains into a cooked or semi-cooked condition, whereby they may be more readily hulled after such treatment, by rendering the grains resistant or glassy in their structure without breaking their cells or destroying the original form, size or identity, to any extent whatsoever. Grains thus treated when dried down to an air-dry condition may be stored for any length of time without danger of deterioration; or, if it be desired, they may be still further treated,-for example, flaked, ground, or out into meal or grits. grains may also be puffed, whereby they become greatly expanded without losing their original shape; in other words, swelled grain is substantially homologous to the natural grain. One method of pufiing grain thus treated I have described inmy co-pending application, Serial Number 370,004 filed April 24, 1907.

The grams, especially rice, when thus The treated become resistant to the rapid escape of their contained moisture. Hence, when in their air-dry condition, they can be puffed and increased many times the size of their original form by rapidly heat-ing them in any suitable manner,-as, parchiog them in hot fat or oil, or in a cornpopper inside of a hot oven. The rains thus parched do not lose their identlty by Patented Aug. 20, 1912.

becoming-everted; nor are they otherwise broken up when swelled. I

In the accompanying drawings I show one form of apparatus suitable for carrying out the herein described procss.

Figure 1 is a side view of the pipin together with a longitudinal sectional e evat1on of the drum-support in the oven, the latter being indicated in dotted lines. Fig. 2 is a rear end view of the arrangement shown in Fig. 1 and Fig. 3 shows the drum in charging and discharging positions, the 1latter position being indicated in dotted mes. a

The material to be treated is put into a drum 2, mounted upon a suitable car capable of being rolled about and brought to the various parts of the apparatus for handling. The car consists of two side members 3, 3, having a trunnion 4 extending therebetween at the'rear end; a shaft or axle 5 connects the forward ends of said members. Small wheels or rollers 6 are mounted outside of the members 3, u on the projecting ends of trunnion 4 and s aft 5. The cars run on a track 7 within the oven consisting of four rails fastened to the inside of the cage 8. At each end of the oven is a ring 9 having teeth outside forming a gear, which meshes with another gear 10 adapted to rotate the cage. The gears 10 and rollers 11 support the cage and inclosed drum, in addition to turning it by any suitable power applied to one of their supporting shafts outside of the oven.

By means of the gears 9 and 10 the cage containing the drum is rotated slowly during the heating. Rotation is permitted by the stuffing box 12 which at the same time maintains 'the steam-connection. The arrangement of the piping shown is as follows; 15, 15", 15, 15 and 15 are valves; 16 is a pressure gage. By opening valves 15 and 15, and closin valves 15 and 15, the steam is by-passe around the-drum. By closing valve 15 and opening 15, the pressure in the drum may be brought to any desired point as shown by gage 16. To reduce the pressure in the drum, valve 15 may be closed, and valves 15 and 15 opened whereby the pressure escapes into the atmosphere. Thus, by roper valve-manipulation the conditions 0 pressure and temperature in the drum may be regulated and controlled absolutely within the desired limits. It will be understood that the oven is heated by any suitable or desired means,as, for example,

as. T Ile lid 18 of the drum is clamped tightly closed, a suitable soft-metal gasket being provided to cause an air=tight connection, when the drum is in the horizontal position in the frame. In order that the heating may not unseal the lid, I prefer to make the drum of bronze, or some material having a higher coeflicient of expansion than the 20 side members of the frame.

After the treatment has been brought to a close, the drum is disconnected at 12, and run out of the furnace to the discharging mechanism, which, by means of an arm 17 suitably connected therewith, lowers the drum about 4 as a pivot. The lid 18, previously held shut by the roller 19, may .now be opened, and the contents discharged. In charging, the drum is raised by the same arm or screw 17 until it tilts upwardly, when the material to be treated may be fed into the drum.

I take hulled rice or paddy rice and add to it a sufficient quantity of moisture, pref- 5 erably-by soaking the grain in cold water until it becomes saturated. When thus saturated, and when all of the excess water has been well drained ofl, the rice contains from 25 to of total moisture. Due to the 4 water imbibed the moisture saturated grains have slightly enlarged, but otherwise they are unchanged in their form and structure. and have not been broken up. A quantity of the rice thus prepared is put into the cylinder sufficient to fill it from one-third to twothirds whereupon the cylinder'is sealed airtight and placed inside the oven where it is kept at a temperature of about 170 de grees C. Or, the cylinder may be steamjacketed, and steam at a pressure of about 60 pounds per square inch may be used for applying the heat. In either case the rice under treatment is not in contact with the steam in the jacket or with the oven flame. but is kept away from the steam, flame and fumes by being inclosed in the air-tight cylinder, receiving only the heat that is radiated from the cylinder wall or the inner plate of the steam jacket.

The cylinder is rotated while heating so that the rice grains will be kept stirring and tumbling, whereby all the grains receive the same amount of heat from the cylinder-wall. As soon as the rice under treatment reaches about degrees (3., the moisture of the 1grain begins to act on the starch granules by ydrating them. Such hydrating act-ion increases with the increasin temperature.

When the .temperature 0 the rice reaches 100 degrees (1, steam begins to form and 70 soon thereafter pressure develops. The treatment is continued until a pressure of about 10 to 55 pounds per square inch has formed, or until the temperature of the rice has reached 110 to 150 degrees C.

During the treatment the grains have not changed their shape, but are found at the end of the treatment in substantially the same condition as when put into the cylinder. Due to the softening of the starch granules by hydration, the whole rice grain has become somewhat softened, and in texture the whole grain is rubbery when pressed between the fingers. The-surfaces of th( grains are not broken, nor are the grains distorted in any way or pasted together as is the case when rice is boiled or steamed b the old methods. The reason for this is evidcnt: During the treatment only enough moisture was present in the grains to hydrate the starch granules in situ and not enough to macerate the grains, as is the case when an excess of water is added to the rice, or when the rice is boiled or subjected to direct steaming. In these events the surfaces of the grains become sticky and broken. By my new process, as herein de scribed, the surface .is left in its natural smooth, unbroken condition.

The rice, treated as above set forth, contains practically the same percentage of moisture as it did when put into the cylinder for treatment-,-a small percentage of the moisture having been lost by conversion into steam confined in the space unoccupied by the rice.

The rice is now ready for the second stage of the operation, which consists in reduc ing the pressure of the cylinder below that, of the atmosphere. This is done by opening the valve which connects the cylinder with the vacuum pump, thus allowing the pressure of the cylinder first to blow oif to normal atmospheric pressure and then creating within the cylinder a vacuum or partial vacuum by starting the vacuum pump. For the sake of simplicity and clearness I have indicated the connections between the drum and the vacuum pump merely in a diagrammatic way (see Fig. 1), inasmuch as it lies within the skill of anyone versed in the art to connect the drum orcylinder with any form of suit-able vacuum pump. The vacuum gage is maintained at about 27 inches of mercury until the rice has dried out to the desired percent-age. Thus, if the rice contained at the beginning of the operation something like 35 per cent of moisture, and it is desired to dry it down to 10 per cent, then 25 per cent would be drawn stopped as soon as the rice is about air-dry.

- grains.

The length of time required to dry the grain is readily determined by practice.

When the desired percentage of moisture has been reached, the operatlon is stopped and the dry grain taken out of the cylinder for storage or for further. treatment, as above described. I

Instead of rice, I may take oats either hulled or unhulled, and saturate the rains with water, as by soaking in water an then draining oil the water not imbibed by the This leaves the grain moisturesaturated, in which condition they contain about per cent of total moisture. Enough of the oats thus treated is 'ut into the c linderto fill it about one ha f. The cylin er is then sealed and run into the oven which is kept at about 170 degrees C. Rotation (if the cylinder is now begun and the heating continued until a pressure of about 25 pounds per square inch develops within the cylinder. This pressure is now reduced slowly by blowing ofl either through the I condenser of the vacuum pump or through the,air. The valve of the vacuum pump attached to the cylinder-connections is now opened and the pressure inside of the cylinder brought to a partial vacuum, sa to 27 inches of mercury, at which point it -1s kept until the oats contains about 10 to 15 per cent moisture. The '0 eration is then completed by stopping an openin the cylinder and taking out the oats. nhulled oats, treated and dried as above described, hull readily by the ,usual oat-hullin machinery and methods of hulling this kin of grain.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States, is:

1. The process of treating cereal grains which consists in tumbling the approximately moisture-saturated grain in an air-tight, heated receptacle until steam is formed square inch has developed wi from the moisture in the grain whereby a pressure develops within the receptacle, and then reducing the ressure to dry the grain down to the desired degree of moisture.

2. The process of treating cereal grains which consists in tumbling the approximately moisture-saturated grain in an airtight, heated receptacle until steam is formed from the moisture in the grain whereby a pressure develops within the receptacle,and then reducing the ressure below atmospheric to expel any esired percentage of moisture.

3. The process of treating cereal grains which consists in tumbling the approximately moisture-saturated grain in an airtight, heated receptacle until steam is formed from the moisture in the graimthen continuing the heating and tum l a pressure of from 10 to pounds per t in the receptacle, and then -reducin the. ressure to dry the grain down to the esire degree of moisture.

4. The process of treatmg cereal grains which consists in tumbling the appro ri mately moisture-saturated grain in an airtight, externally heated receptacle until steam is formed from the moisture 1n the grain, 'then continuing the heating and tumbling until a pressure of from 10 to 55 pounds per square inch has developed within the receptacle and the grain becomes hydrated, and then reducing the pressure below atmospheric to expel any desired percentage of moisture.

5. The process of treating cereal gra ns which consists in saturating the gram with moisture, heating the grain in a closed receptacle until steam is developed from the moisture in the grain, continuing the heating to develop pressure, while st rring and tumbling the grain, and then rellevmg the pressure in the receptacle and creating a vacuum therein to dr the product.

In witness whereo I have hereunto subscribed my name in the presence of two witnesses.

ALEXANDER P. ANDERSON. Witnesses:

A. A. Tuoms, C. L. Horxms.

ing until 

